I think TKR matched the original series without too obvious contradictions (I don't know the details since I only saw two episodes of TKR) so TKR could be no problem. The Team could show up as a cameo.
KR2000 had a so sci-fi-ish world, it didn't match. I can't imagine another Knight Rider story in that continuity. But, sadly, Devon's death is something that cannot be done any other way now (except for an off-screen death).
I don't know anything about KR2010.
KR(2008) could be ignored when the recently announced remakes (like Fantastic Four) come out and if they are accepted. But it's not likely to be ignored.
I think it's not the storyline that matters, it's the "Man of six words" (
http://www.imdb.com/title/tt0083437/trivia?tr0723132) concept that needs to return. All the sequels have the "Humans driving a fantastic car" concept instead of the "Man of six words".
Also a complete restart would be nice, if it is done well, done with respect, and done professionally. Something like Transformers Animated: it had sooo many cameos and references without any actual in-story explanations, and it WORKED.
Edited to add after reading the comments: Wasn't the fate KITT suffered at the beginning of / before KR2000 the fate KARR was meant to suffer, what KARR was running from? Being shut down and thrown away piece by piece? Ironic! (And very evil, but I don't think that needs to be explained.)